Fig. 6.

Introduction of an EGFR signaling cascade increases the expression of PTHrP and phosphorylation of EGFR Tyr992. (a) MCF7 cells were infected with an LXSN vector control recombinant retrovirus of with the LXSN-EGFR recombinant retrovisur, resulting in the MCF7 vector control and MCF7/EGFR cell lines, respectively. The MCF7/EGFR and vector control cells were incubated with EGF (10 nM) or 100 nM AREG (AREG) for 6 h. The mRNA was harvested from three independent cultures. This experiment was repeated twice. (b) The cells were stimulated with 10 nM EGF or 100 nM AREG. The glycoproteins in protein extracts were precipitated with concanavalin A sepharose and resolved by SDS-PAGE. The immunoblots were then probed with the corresponding antibody. This experiment was repeated twice. *P < 0.01 vs. EGFR unstimulated